TABLE 2.

Comparisons of the quantities of amino acids taken up or released by S. aureus at the mid-exponential phase of growth under optimal conditions (A) compared with growth under sub-optimal environmental conditions (B–D).

Amino	(A) Control pH7 at 37°C with no		(B) pH7 at 37°C with 2.5%		(C) pH6 and 35°C with no		(D) pH8 at 35°C with no
acids	added NaCl. nmole/100 μL		NaCl added. nmole/100 μL		added NaCl nmole/100 μL		added NaCl nmole/100 μL
	Taken up	Released	Taken up	Released	Taken up	Released	Taken up	Released
LYS	74.2 ± 14.9		17.0 ± 37.5*		2.6 ± 12.2*		15.1 ± 17.3*
LEU	70.9 ± 28.8			24.0 ± 34.1*	17.1 ± 21.2*			6.4 ± 27.4
SER	56.3 ± 5.8		26.9 ± 5.9*		26.6 ± 4.4*		61.6 ± 4.4
PHE	41.9 ± 11.6		1.4 ± 16.7*		10.4 ± 5.1*		11.3 ± 11.2*
GLU	34.2 ± 3.8		9.0 ± 4.00*			0.8 ± 5.6*	34.0 ± 3.6
VAL	30.0 ± 8.4			7.0 ± 12.4*	1.4 ± 7.9*		3.0 ± 7.2*
THR	29.6 ± 3.4		15.2 ± 5.4*		18.2 ± 5.0*		29.2 ± 2.8
ALA	28.5 ± 4.5		6.5 ± 7.8*		6.7 ± 4.6*		15.2 ± 5.2*
ASN	27.3 ± 2.0		16.2 ± 2.9*		14.2 ± 2.3*		28.9 ± 1.4
GLY	25.9 ± 1.9		25.9 ± 1.6		25.0 ± 1.7		33.9 ± 1.2*
ILE	23.0 ± 5.5			0.5 ± 5.0*	2.2 ± 5.6*		13.2 ± 4.7*
TYP	19.1 ± 4.3		2.1 ± 5.8*		1.7 ± 3.9*			0.03 ± 4.9*
MET	18.8 ± 3.5		4.2 ± 5.6*		2.3 ± 6.2*		9.6 ± 3.5*
ASP	10.7 ± 1.8		7.3 ± 0.9*		9.4 ± 2.3*		11.2 ± 2.0*
TRP	10.7 ± 2.9
HIS	5.2 ± 1.5		2.2 ± 1.4*		0.4 ± 1.3*		0.5 ± 1.2*
TPR	4.6 ± 2.1		1.8 ± 0.4*		1.9 ± 0.67*		0.5 ± 0.4*
HYP	4.1 ± 0.0		0.7 ± 1.6*		0.2 ± 0.31*		3.7 ± 1.6
PRO	3.2 ± 0.9		7.1 ± 0.4*		2.1 ± 0.65		3.0 ± 0.7
ABA	2.4 ± 1.9		3.4 ± 0.2		2.0 ± 0.11		0.9 ± 0.2
GLN		5.0 ± 6.7		24.8 ± 11.8*		8.2 ± 3.4		14.6 ± 6.0
AAA		1.5 ± 2.5		5.8 ± 3.0		3.6 ± 1.4		6.0 ± 2.2
ORN		0.45 ± 0.4		2.4 ± 0.7		0.5 ± 0.2		0.1 ± 0.5

The amino acids have been ranked in the order of their magnitudes of uptake measured at ideal growth conditions (mean ± SD, P < 0.05). *Indicates amino acids are significant.